Automatic reclosers and sectionalizers



Feb. 24', 19 9 L. v. CHABALA 2,875,381

AUTOMATIC RECLOSERS AND SECTIONALIZEIRS Filed Nov. 27, 1953 2 Sheets-Sheet 1 Fig.|.

INVENTOR Leonard V. Chobolo. 2

' BY (5 5 5 2/ ATTORN United States Patent 2,875,381 AUTOMATIC RECLOSERS AND SECTIONALIZERS Leonard V. Chabala, Pittsburgh, house Electric Corporation, poration of Pennsylvania Application November 27, 1953, Serial No. 394,813 3 Claims. (Cl. 317-22) Pa., assignor to Westing- East Pittsburgh, Pa., a corgenerally to circuit interrupters, particular to automatic reclosers provide an operator for single-pole reclosers and sectionalizers which readily provides for three-pole operation thereof.

Another object of my invention is to provide an operator for sectionalizers and reclosers which may be easily attached to such devices as are already in service.

It is an important object of my invention to provide an operator which may be quickly attached to a sectionalizer or recloser merely by securing it by means of the cover bolts thereof. 1

Yet another object of my invention is to provide for interlocking three single-phase circuit interrupters by means of operators individual to each interrupter and mounted externally of the interrupter casing and Without requiring any complicated mechanical connections therebetween.

Other objects will in part be obvious, and will in part be explained hereinafter.

In practicing my invention in one of its forms, each sectionalizer or recloser is provided with an operator secured thereto by means of a bracket secured by the cover bolts. The operator has an armature sl'idable on a rod connected to the handle and is provided with a solenoid for actuating the armature to move the handle out of toggle and lock the contacts open. A switch actuated by the rod of each device when it is opened manually, or by its counter, is connected to provide operating circuits for the solenoids of the other devices.

For a more complete description, reference may be made to the following detailed description, which may be read in connection with the accompanying drawings, in which:

Figure 1 is a schematic diagram showing the invention applied to a polyphase circuit with a sectionalizer em' bodying the invention, shown in vertical section;

Fig. 2 is a partly sectioned side el'evational view of a reclosing circuit breaker embodying the invention; and

Fig. 3 is a reduced front elevational view of the circuit breaker of Fig. 2.

Referring to Fig. 1 of the drawings, it will be seen that while three sectionalizers are shown only one is shown in detail since the others are identical, and the one sectionalizer 17 is here shown as being enclosed within a metal tank 27, which is provided with an insulating liner 28, and which is surmounted by a top casting 29.

This sectionalizer may be substantially similar to that described in detail in the copending application Serial No. 189,082 of James M. Wallace, now Patent No. 2,752,453 which application is assigned to the assignee of the present invention. As therein shown, anincoming line 15 entersthrough a bushing 31 which terminates inside of the tank. The circuit then continues, through a con ductor 32 to a sectionalizer coil 19. From the sectionalizer coil 19, the circuit continues through a conductor 33, separated from conductor 32 by insulation 30, back underneath the bushing 31 for the incoming lead 15, and thence to the terminal 34 which constitutes one of the stationary contacts of the sectionalizer which are disposed to be engaged by a movable bridging contact 20. Ordinarily, the sectionalizer has two bushings, each with its lead passing through the bushing, and each bushing terminates, at its bottom, in one of the stationary contacts of the sectionalizer, bridged by contact 20, but since the drawing shows an approximate central section through the sectionalizer, the second stationary contact is not visible. The movable contact 20 is shown as a contact bar or bridge which presses up against the underside of the stationary contact 34 and the other stationary contact (not shown) in the closed position of the sectionalizer, and which is lowered by gravity, to operate the sectionalizer, upon the release of a pull rod 36, which is shown in the form of an upwardly extending insulating tube.

The sectionalizer 17 can theoretically operate either in air, or in an insulating oil, or other insulating fluid. It is sometimes desirable for the counter 37 to operate in oil, as it involves dashpot or fluid flow operation, as subsequently described, which is somewhat more diffi cult to obtain in air, with the necessary time-constants. It is sometimes desirable to have the contacts 3420 also operating in oil. Consequently, the apparatus is, by way of example, illustrated as having the counter 37 and the contacts 34-20 immersed in oil 40 which is contained in the tank 27. A counter-and-l'ockout mechanism 23 is segregated, into its component parts, consisting of the counter 37 and the operating mechanism 38.

The operating mechanism comprises a bellcrank trigger 53 mounted on a pivot 50 supported by a bracket 51 depending from the top casting 29, and disposed to support one end of a lever 47 which is pivotally supported at the other end by a fixed pivot 48 carried by bracket 51, and carries a pivot 44 which comprises one of the terminal points of a triangular lever 43. A toggle mechanism, including a lever 46 pivotally connected to the lever 43 by a pivot 45, and an operating handle 60 pivotally supported on the casting 29 by a pivot 61, comprises the other terminal point of support for the lever 43. The pull rod 36 is connected to the lever 43 by a pivot 42. The trigger 53 has a downwardly extending abutment-portion 56 which is adapted to be tripped when an upward movement of a trip pin 57 of the counter 37 raises said abutment point 56 of the trigger, whereupon the linkage of the operating mechanism permits the pull rod 36 and the movable-contact member 20 to drop freely in the opening operation of the mechanism.

The counter 37 is suspended from the top of the top casting 29, by means of a plurality of depending insulating supports or tubes 70, which support a base plate 71 of the counter.

The counter proper 37 comprises a vertically disposed tube 72, which is preferably made of brass or other nonmagnetizable metal. The lower end of the tube is disposed to be closed by a plug 73 of iron or other magnetic material, while the top of the tube 72 is open. The series current-coil 19 surrounds a portion of the tube 72, inter mediate between itsupper and lower ends. Immediately above and below the coil 19 are two perforated magnetizable plates 74 and 71, respectively, both of which are perforated so as to surround the tube 72. The plates 74 and 71 are joined by bolts 75 and serve as the two pole pieces of an electromagnetic circuit, the excitation of which is provided by the coil 19. I

:Inside of the tube 72 is a magnetizable core or armas ture 76, which is slidably movable, with a close fit of say perhaps 3 mils radial clearance, within said tube. The armature 76 normally extends partly above and partly below the level of the upper plate 74, being located by means of a shoulder 69 in the tube, while the plug 73 is disposed partly above and partly below the lower plate 71. Both the armature 76 and the plug 73 thus extend partly within and partly without the space beween the two plates 74 and 71.

As disclosed in the Wallace application, the armature 76 may comprise two relatively movable elements, name- 1y, a core 77 of iron or other magnetic material having a cylindrical extension 73 at the upper end, and a movable cap or piston 80 of anon-magnetic material, such as brass, closely surrounding the extension. A compression spring 79 is disposed between the core 77 and the plug 73, so that when the coil 19 is sufiiciently energized, such as by a fault current, the core 77 is drawn downwardly towards the plug, storing up energy in the interposed compression spring 79, as will be more fully described hereafter.

Both the core 77 and the plug 73 are provided with central bores 81, and the lower end of each of these bores is provided with an orifice closable by means of a ball valve 82, so that the fluid which is entrapped within the closed lower end of the tube 72 resists any rapid downward movement of the piston 80, because of the closing of the ball valve 82 in the plug 73, while the valves permit the free upward movement of the piston 80 and core 77. The entrapped fluid could be any gas or liquid having the required viscosity in comparison with the mechanical clearances which are provided. The idea is to permit the respective core 77 and piston 80 to move freely upwardly, in a step-by-step motion, as will be subsequently described, while permitting the piston 80 to drift back downwardly again, by fluid leakage, at a very slow rate.

At the top of the armature 76 on the piston 80, is aifixed an upstanding pin 83, which extends upwardly to a point above the open top end of the tube 72. This pin 83 is surrounded by a tubular tip or trip pin 57, which is capable of serving as an adjustable vertical extension of the pin 83. This vertical adjustment is efiected in any one of a plurality of vertical spaced positions corresponding to the spacing between the core 77 and the plug 73, by means of a cotterpin 84, so that adjustment may be made for any desired number of counts, such as 1, 2, 3 or 4, within the range of the counting-mechanism 37.

In the operation of the counting mechanism 37, when the coil 19 is first energized with a current corresponding to the setting of the counter, the core 77 of the armature 76 is drawn downwardly toward the plug 73, so as to close the air gap which separates the inner ends of said armature and plug. The fluid between the core 77 and the plug 73 cannot move downwardly because of valve 82 in plug 73. Hence, in order to permit the armature and plug to come together, the fluid between the armature and plug is forced upwardly through the check valve 82 in the core 77, and hence the piston 80 must remain in its initial position while the core 77 moves downwardly. When the coil 19 is deenergized, spring 79 returns core 77 to its initial position against shoulder 69. Oil is drawn in through orifice 81 in plug 73, and the oil trapped above valve 82 in core 77 lifts piston 80 up with core 77 to advance it one step.

In order to provide for using a plurality of such sectionalizers 17 on a three-phase circuit, eachsectionalizer may 'be provided with an operator 85 which may be contained in a weathelproof housing 86 mounted beneath the handle 60 by means of a U-shaped bracket 88 which may be attached to different ones of the bolts 89 securing the tank- 27 to the cover casting 29. A solenoid 90 may be mounted on a bracket 91- in the housing having an? armature 92. The armature 92 is slidably mounted asraaet on a rod 93 which extends upwardly from the housing and isconnected to the handle 60 by a clevis 94 straddling the handle, and a pin 95. An eye 96 is provided at the lower end of the rod 93 which projects through the bottom of the housing where it is readily accessible to a hook stick or the like. The rod 93 is provided with a shoulder 93 having a spring 98 interposed between it and the armature. A flexible bellows 97 of synthetic rubber or the like seals the rod 93 where it passes through the top of the housing.

An auxiliary switch 99 has a resilient contact arm 99c normally engaging a stationary contact 99a and provided with an operating projection 99d for actuating it to engage contact 9%. A spring actuator 992 is secured to the base 99 of the switch for engagement with a shoulder 9 on rod 93.

As shown in Fig. 1, each solenoid may be connected by a conductor 18 to one conductor 21 of a source of control voltage, and thence by a conductor 22 to contact 99a. Contact 990 is connected to an intermediate conductor 16. Contact 9912 is connected by a conductor 24 to the other conductor 25 of the source, so that operation of any switch 99 connects the solenoids 90 of the other sectionalizers between the conductors 21 and 25 of the source for opening the other sectionalizers.

When there is a single-phase fault on the distribution line, within the protective reach of an automatic reclosing circuit breaker or recloser located between the sec tionalizer and asource of electricity, the core 77 is pulled downwardly and the recloser contacts of the particular phase 5 quickly opens, and quickly again recloses, but during the moment (12 cycles or more, in a 60-cycle line) when said recloser contact was open, the sectionalizer coil 19 is deenergized, reducing the attractive force between the armature 76 and plug 73. The compression spring 79 between the core 77 and plug 73v expands, and pushes the core upward again, to the normal separation distance. During this action, however, fluid in the armature 76 is entrapped and cannot move downwardly, because of the fluid flow valve 82 in the core '77, and hence the piston and the core 77 must move upwardly together, which they are free to do, so far as fluid action is concerned, because the lower valve 82 in the plug 73 will open during such movement. The piston 80 of the armature 76 is notched upwardly by a distance corresponding to approximately the amount of compression of the spring 79.

If a fault continues on the distribution system, at a point beyond the sectionalizer coil 19, the reclosure of the recloser contact reenergizes the sectionalizer coil 19 and causes a second compression of the spring 79, in a manner already described. It the fault is still on the system, as has just been assumed, the recloser-contact again opens, and a second upward stepping movement of the trip pin 57 is obtained. Thus the step-by-step movement of the counter mechanism continues.

When the last upward stepping of the piston 80 of the armature 76 is obtained, depending upon the vertical positioning of the trip pin or tubular tip 57, this pin 57 comes into contact with the trigger 53 during this last upward'rnovement, and trips out the sectionalizer contact 20. 'It will be noted that this last upward movement of the trip pin 57 occurs during-a time when the current in the sectionalizer coil 19 is ofl. In the operation of the recloser, the current remains ofi', that is, the recloser contact remains open for a minimum of twelve cycles (on a 60-cycleline), before the recloser contact recloses. The opening of the sectionalizer-contact 20 requires something like twoor three cycles, so that it is seen thatthe sectionalizer contact 20 opens during the current-oft period, so that the sectionalizer contact 20 does not have to'interrupt any substantial current.

Asthe onesectionalizer-l7 opens, its rod 93 is actuated downwardly, moving. contact- 990 to engage contact 99b. This: provides; an obvious circuit for energizing-the sole armatures 92 downwardly to effect a suflicient blow on .shoulder 93' to break the toggle relation of levers 60 and 46, thus opening the other sectionalizers. In the event of other than a single phase fault, the reclosers of the faulted lines will each trip their respective sectionalizers, thus preventing any sectionalizer from having to interrupt fault current.

My invention may also be applied to other types of circuit interrupters, and in Fig. 2 is shown as applied to a reclosing circuit breaker of the type disclosed in Pat ents 2,626,329 of James M. Wallace et al., and 2,622,167 of H. L. Rawlins et al., wherein the breaker is illustrated as being mounted in a metal tank 102 having a closed ,bottom wall and an open top. Preferably, the tank is adapted to be lined at least over the bottom wall and up to a point adjacent the open top of the container with a liner 103 of insulating material such as fiber, or the like, and is filled up to the level L with liquid, preferably a liquid having arc extinguishing ability such as oil. The upper end of tank 102 is provided with an outwardly extending flange 104 on which the flange 108 of a cover casting 106 is adapted to be seated, preferably, with a gasket 110 interposed therebetween. The cover may be secured to the tank in any desired manner, such for example, as by bolts 113.

The breaker contacts and certain of the contact actuating mechanism are adapted to be supported in tank 102 from cover casting 106 by means of a pair of integral supporting lugs 116 (only one of which is shown) depending from the top wall of the cover casting and adapted to engage insulating spacer rods 118 having threaded studs (not shown) engaging threaded openings in rods 118 and lugs 116 on supporting casting 120. A supporting plate 122 may be supported in a similar manner from casting 120, so that a solenoid coil 124 may be mounted between casting 120 and supporting plate 122, with the central opening in the coil aligned with openings provided in casting 120 and plate 122.

Spaced stationary contacts 126 of the breaker are each supported from plate 122 by a support tube 128 of insulating material, such as fiber, with the stationary contacts being mounted on support 128, by means of screws 130 and with the upper end of the support 128 having brackets 132 by means of which the support is secured to supporting plate 122.

Stationary contacts 126 are adapted to be closed by engagement therewith of a bridging contact 136 having contact tips 138 at opposite ends thereof for engagement with the stationary contacts, respectively. Bridging contact 136 is supported substantially centrally on a slidable contact actuating rod 144 by pivot pin 140 for limited pivotal movement about a transverse axis on contact actuating rod 144. Contact rod 144 should be of an insulating material such as fiber or a molded insulating material.

The upper end of contact actuating rod 144 has a pair of connecting links 146 positioned at each side thereof and pivoted thereon as by a pivot pin 148, with the upper ends of these connecting links mounted on a common pivot pin 150 for a pair of toggle levers 152 and 154. Toggle levers 152 and154 are both formed of sheet material, with lever 152 being flat and lever 154 being bent to substantially channel form with outwardly extending flanges 156 adapted to be received at the free ends thereof in recesses 158 provided in the spaced downwardly depending fingers of an angled supporting bracket 160 which, in turn, is secured to a lug 162 integral with the cover casting. Preferably, the base of the channel part of. toggle lever 154 is extended at 166 through the space between the supporting fingers of bracket 160, and at the other end of lever 154 the sides of the channel formation thereof are extended to be mounted on pivot pin 150. A coil tension spring 168 has one end hooked into an opening provided in toggle lever 152, and has the opposite end thereof hooked over a spring support on the cover casting.

Solenoid coil 124 previously mentioned is adapted to be energized under certain conditions for automatically opening the circuit breaker contacts. The coil 124 has a central opening provided with a cylindrical sleeve 174 in which a solenoid core 176 is adapted to be slidably mounted in a piston-like manner.

For any given rating of circuit breaker, solenoid coil 124 is designed to become sufficiently energized when the load current in the circuit exceeds its rating as to attract core 176 and move it upwardly within sleeve 174. When core 176 commences its upward travel, bridging contact 136 being held engaged by toggle spring 168, does not move until the upper end of bushing connected to'armature 176 by a tube (not shown) strikes a collar 181 secured to rod 144. Thereupon actuating rod 144 moves upwardly, and the force exerted by toggle spring 168 begins to decrease and in a very short distance has substantially no value at all. When the breaker contacts have attained their full open circuit position, the parts associated therewith are biased to return by gravity.

In order to limit the number of operations of the circuit breaker in close succession upon the occurrence of a continuing overload on the circuit and to provide for manual operation, means are provided for holding the breaker contacts open in response to the occurrence of a predetermined number of closely succeeding circuit interrupting operations, which means can be manually actuated. This means comprises a toggle lever 204 pivoted at one end as at 206 on a U-shaped spring lever 208 which, in turn, is pivotally supported as at 210 between the legs of a U-shaped supporting bracket 211 secured to cover casting 106. The other end of toggle lever 204 is pivoted, as by a pivot pin 212, to the adjacent end of a second toggle lever 214, and this, in turn, is mounted on a pivot pin 216 intermediate its ends, with the pin 216 being mounted in a bracket 218 secured to the adjacent wall of cover casting 106. A slot 220 is provided through the cover casting 106 for receiving the other end of toggle lever 214 which acts as a manual operating handle at the exterior of the circuit breaker casing, being provided with an angled hook end 222. A coil compression spring 224 is mounted to react between the bight of lever 208 and cover casting 106. Normally, toggle levers 204 and 214 are held by spring 224 with pivot 212 below the center line connecting pins 206 and 216, with the outer end of lever 214 positioned in and beneath an integral hood 226 on cover casting 106, in engagement with an adjustable stop screw 228 mounted in the hood.

In the position of toggle levers 204 and 214 illustrated, they have no effect on operation of the circuit breaker as previously described, being normally inactive in this respect. However, lever 208 has a connecting pin 213 extending beneath toggle levers 152 and 154. Accordingly, if it is desired to manually open the circuit breaker contacts, a hook stick or similar operating member may be engaged With the upper side of angle hook 222 of toggle lever 214 and pulled downwardly to rotate the toggle lever in a counterclockwise direction about its supporting pivot 216 to move toggle levers 204 and 214 overcenter in an upward direction, and in doing this, pin 213 engages toggle levers 152 and 154 and moves them upwardly in a counterclockwise direction, thus carrying contact actuating rod 144 upwardly to separate bridging contact 138 fromstationary contacts 126. The contacts will be held open by spring 224 which maintains toggle levers 204 and 214 in their upper overcenter position. In thus manually opening the circuit after toggle spring 168 is moved to its on-center position, it will be observed that the spring 224 is only required to maintain the contacts of the breaker open against the relatively light closing bias due to gravity, and such light bias as may be due to toggle spring 168 in the event that toggle levers 152 and 154 are stopped just prior to reachgar ens ing'their on-center position. With the breaker contacts maintained at their open circuit position following the manual circuit opening operation described above, it will be apparent that the outer end of toggle lever 214 projects below hood 226 of cover casting- 126 so as to provide a readily visible indication that the breaker contacts are maintained at open circuit position. It will further be apparent that the breaker contacts may then be closed only by manual operation of toggle lever 214 in the opposite direction, that is, by exerting an upward force on the outer end of the toggle lever by engagement of a hook stick or the like with the underside of-hook 222, to rotate lever 214 in a clockwise direction to move it and toggle lever 264 back overcenter to the full line position illustrated on the drawings.

An integrating mechanism for automatically moving toggle levers 2% and 214 upwardly overcenter and thus preventing reclosure of the circuit breaker in response to a predetermined number of closely successive circuit interrupting operations is provided comprising a cylindrical tube 230 clamped or otherwise secured in a lateral extension of casting 120 at the top of solenoid coil 124. An integrating piston 236 is mounted in tube 230 and normally rests on the upper end of plug 232, being provided with areduced extension 238 at the upper end thereof having a plurality of spaced circular flanges 240 forming rack teeth thereon, and having an elongated extension 242 of insulating material on the extreme outer end thereof which is positioned below an extension 243 on toggle lever 204. A pawl lever 244 is pivotally mounted at one end as at 246, this end of pawl lever 244 being split with legs located at each side of tube 230 and with pivot 246 supported on spaced supporting flanges 24S integral with casting 120. Pawl lever 244 has a connecting web intermediate its ends, and at the other end thereof the sides of the lever are extending outwardly and laterally as at 248, to normally be in engagement with a shoulder 250 of bushing 185 mounted on the actuating tube of armature 176 adjacent the outer end of this tube. Pawl lever 244 is normally biased into engagement with shoulder 250 by a coil tension spring (not shown). Pawl lever 244 is provided with a pawl member 254 pivoted thereon as at 256, and biased in a counterclockwise direction to a position wherein a portion of pawl member 254 engages the connecting web of pawl lever 244.

When the circuit breaker operates to open the circuit, shoulder 25% will be carried upwardly with armature 176 and thus carry the free end of pawl lever 244 upwardly with it to move pawl member 254 into engagement with the upper one of flanges 240 on integrating piston 236 to thus carry the piston upwardly a predetermined distancc. When the breaker recloses following such a first circuit interrupting operation, integrating piston 236 is left at the position to which it was advanced since'pa'wl member 254 is free to disengage circular flanges 240, and if the breaker remains closed, integrator piston 236 will slowly reset to the position shown in Fig. 1 due to leakage of liquid in cylinder 236 below piston 236 through the relatively small clearance between the cylinder and piston. However, if the breaker immediately reopens after a first opening and reclosing operation, piston 236 will remain advanced, and pawl member 254 this time will engage the next lower circular flange 240 on the integrator piston and raise the piston a further amount. Subsequent reclosing will result then in leaving piston 23s at a further advanced position from which it eventually will reset if the breaker remains closed. However, in the event of a continuing overload, the breaker will again open and reclose and the pawl member 2S4 advances integrator piston 236 an amount sulficient to cause the upper extension 242 thereof to engage the extension 243 of toggle lever 204 and move this lever upwardly overcenter, so that toggle spring 224 8 will maintain the contacts separated in the manner previ ously described. It is thus apparent that toggle levers 204 and 214 will be automatically moved upwardly overcenter to maintain the breaker contacts separated only in response to a predetermined number of closely successive circuit opening and closing operations, usually four such operations, however, in the event a lesser number of closely successive opening and closing operations occurs, the integrating mechanism will reset and the breaker contacts will be automatically held open only when the aforesaid predetermined number of opening and closing operations occurs in close succession. Obviously, after the'breaker contacts have been automatically actuated to a position where they are held open by toggle spring 224, they can be reclosed only by manual operation of toggle lever 214 in the manner previously described.

By mounting an actuator of the type hereinbefore disclosed on the circuit breaker by means of a U-shaped bracket 83 and cover bolts 113 as shown in 'Fig. 3', and connecting rod 93 thereof to the handle 222, the auxiliary switch 99 thereof will be actuated upon lockout of one circuit breaker, to provide energizing circuits for the solenoids 96 of the other circuit breakers when arranged in the manner shown in Fig. 1, so that three single-phase reclosing circuit breakers may thus be readily used on a three-phase circuit to prevent single phasing of three phase equipment. 7

From the above description and the accompanying drawings, it will be apparent that we have arranged in a simple and effective manner for three-phase operation of single-phase sectionalizers and rec'losers. My invention requires no modification of existing equipment and may readily be applied to apparatus'already in use and of the type having a manual operating mechanism with a handle extending from the interrupter casing, which handle operates when the contacts are locked open. Three-phase installations of single-phase interrupters may thus be inexpensively and effectively made.

I claim as my invention:

1. In a polyphase circuit; a circuit interrupter for each phase of the circuit each having separable contacts in a container, with electro-responsive means individual to each interrupter for efiecting separation of its contacts in response to an overcurrent, said. contacts being biased to reclose following such separation, manual operating means for each interrupter including a handle projecting from the container, lockout means for each interrupter for locking the contacts open, a counter individual to each interrupter for actuating the manual operating means and lockout means in response to a predetermined number of closely successive openings; an operator individual to each interrupter disposed in a housing detachably mounted on the container and having a solenoid with an armature having a lost motion connection with the handle; a switch individual to each operator disposed in said housing and having contacts operated by said lost motion connecting means; and a circuit including said contacts connecting the solenoids so that whenever one interrupter is. locked open its switch provides an energizing circuit for the solenoids of the other interrupters.

2. In a polyphase circuit; a circuit interrupter for each phase of the circuit each having separable contacts in a container with an operating mechanism therefore suspended from a cover for the container, manual operating means for each interrupter including'a pair of toggle levers one of which hasa handle portion projecting from its container and the other of which is connected to the operating mechanism for opening and closing said contacts, releasable means individual to, each interrupter for opening itsv contacts, a counter individual to each interrupter having a member advanced by a predetermined number of successive interruptions of an overcurrent' on its phase to recontainer adjacent the handle of the interrupter; means detachably securing the housing, container and cover; a solenoid in each housing, an operating rod connected to the handle and having an armature thereon for the solenoid; a switch in each housing having normally open and normally closed contacts; a circuit including said normally closed contacts connecting the solenoids in parallel; and a circuit including the normally open contacts of an in terrupter which is open, connecting the aforesaid circuit to a source of electrical energy.

3. In a circuit interrupter, a casing, 21 cover for said casing, means for securing said cover to said casing, separable contacts supported in said casing from said cover, electro-responsive means supported in said casing from said cover, an operating mechanism for actuating said contacts including a member actuated by said electro-responsive means and a handle extending from the cover for operating the contacts to open or close them, an operator including a weatherproof housing mounted on the casing by the securing means for the cover, an operating rod slidably extending through the housing and having a shoulder, means for detachably connecting the rod to the handle, a solenoid in the housing having an armature slidably disposed on the rod to engage the shoulder and actuate the rod, a spring providing a resilient driving connection between the shoulder on the rod and the armature, a switch in the housing actuated by the rod, and circuit means for connecting the solenoid in circuit with said switch,

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